1. Field of the Invention
The present invention relates to an optical multiplexer/demultiplexer for multiplexing or demultiplexing optical signals in a WDM optical communication system or the like.
2. Related Background of the Invention
A Wavelength Division Multiplexing (WDM) optical communication system for transmitting multi-wavelength optical signals through an optical transmission path by multiplexing uses an optical multiplexer/demultiplexer for multiplexing or demultiplexing multi-wavelength optical signals. The optical multiplexer/demultiplexer disclosed in U.S. Pat. No. 6,661,948 permits selection of an input or output port for respective wavelength components, and is suitably used in an optical communication network in which transmission paths of optical signals and wavelengths of optical signals are flexibly determined.
The optical multiplexer/demultiplexer disclosed in U.S. Pat. No. 6,661,948 has a wavelength separator for spatially separating an optical signal fed through an input port into respective wavelength components, and rotatable mirrors for optionally selecting an output port for each of the wavelength components separated by the wavelength separator. Namely, an output port from which a wavelength component is outputted is determined by an angle of rotation of each rotatable mirror.